Phytomyza sp. 5

(Fig. 221)

Material examined. MASSACHUSETTS: Hampshire Co., Cummington, 10.vi.2015, em. 16.iii.2016, C.S. Eiseman, ex Caltha palustris, #CSE2247, CNC654248 (1♀) .

Host. Ranunculaceae: Caltha palustris L.

Leaf mine. (Fig. 221) Upper surface, gradually widening, entirely linear; whitish with diffuse brown discoloration; frass black, initially in widely spaced grains, later in alternating irregular strips.

Puparium. Black; formed outside the mine.

Comments. This is the first published record of an agromyzid reared from Caltha in North America. Spencer (1969) reported two leaf mines from Canada that were attributed to undetermined Phytomyza species, one of them a short linear mine that widened considerably at the end, and one a dark brown blotch along the leaf margin. Four Caltha -feeding Phytomyza species are known in Europe, of which only P. calthophila Hering forms an entirely linear mine (Ellis 2017). The adult from Massachusetts does not match the description of any of these, or of several undescribed Caltha feeders known from Canada (Lonsdale, unpublished data). It is entirely dark with just 1 ors and 1 ori, with a slightly medially widened orbital plate.